It is well known that plants tend to bend towards the light so that a plant must be rotated frequently or it will grow lopsided. It is also well known that a plant's water requirements change with the growing season and with ambient temperature and relative humidity. Optimally, the plant should be rotated more frequently than it is watered. A fixed once or twice-a-week plant rotation and watering program is not conducive to best plant growth but it is better, in most cases, than waiting for them to droop.
Hanging plants are popular because they take up very little living space. Hanging plants are frequently under rotated and over or under watered because they are difficult to reach. Because of these difficulties, there have been a number of spring loaded devices proposed for indicating that a hanging plant has dried out. There is also one patent (U.S. Pat. No. 4,216,619 to Espy) which discloses a spring loaded device for rotating a plant as well as for indicating dryness. In the later case, axial deflection of a helically coiled spring is converted into linear motion by means of a spiral shaft. Friction among the working parts has kept the device from having practical utility.